At least three people were injured in northern Chile. The quake was also felt in Bolivia.

The 12 people killed were crushed by falling debris in the southern city of Arequipa, institute physicist Cesar Jimenez said. Arequipa is located 465 miles southeast of Peru's capital, Lima.

There were conflicting reports on the quake's magnitude.

The U.S. Geological Survey's National Earthquake Information Center in Golden, Colo., said a 7.9 magnitude quake was registered off the coast of Peru in the Pacific Ocean, 120 miles west of Arequipa. Peru's Geophysical Institute put the quake's magnitude at 6.

Radioprogramas radio reported that another eight people had died in the nearby city of Moquegua, but those deaths could not be immediately confirmed.

Images broadcast by Canal N television from Arequipa showed parts of a historic building crumbled in the central square. Many homes had also collapsed in the southern city of Tacna, near the border with Chile.

Radio reports said Arequipa's main hospital was attending to "minor injuries."

At least five aftershocks were reported.

In Chile the most affected city was Arica, 1,250 miles north of Santiago, the capital.

The Emergency Office spokeswoman, Carmen Fernandez, said some houses sustained some damage there, and electricity and telephone services were interrupted.

Arica Major Carlos Valcarce said three people were injured, including a woman who suffered a broken leg when part of collapsing wall fell onto her.

Regional governor Sonia Castillo said "there are no indications" that a tsunami may follow the earthquake.

Peru is intermittently shaken by earthquakes, and was battered by a 7.7 magnitude temblor in May 31, 1970, that killed approximately 70,000 people.

On November 12, 1996, 17 people were killed and some 1,500 injured in a 7.7 magnitude quake that struck Nazca. On May 30, 1990, 137 people were killed in a 6.3 magnitude quake in northern Peru.

A quake with a magnitude of 7 or more is capable of heavy and widespread damage.